A Research Study on the Effects of NNC0537-1482 in Participants With Heart Failure

The study is testing a new drug (NNC0537-1482) to potentially treat people with heart failure. The purpose of the study is to see if NNC0537-1482 is safe and how it works in the body. Participants will either get NNC0537-1482 or placebo (a "dummy drug" without any active ingredients) and which treatment they get is decided by chance. This study will last up to 64 days with an additional screening period up to 28 days.

Inclusion Criteria: * Informed consent obtained before any study-related activities. Study-related activities are any procedures that are carried out as part of the study, including activities to determine suitability for the study. * Male or females of non-childbearing potential. * Age 40-75 years (both inclusive) at the time of signing the informed consent. * Body Mass Index (BMI) range 18.5 - less than (\) 40 percentage (%) documented by echocardiography at screening, or within 12 months prior to screening with no change in clinical status suggesting potential for deterioration in systolic function. AND at least one of the following: * N-terminal pro type-B natriuretic peptide (NT-proBNP) ≥125 picogram per milliliter (pg/mL) (for participants with sinus rhythm) or NT-proBNP ≥375 pg/mL (for participants with persistent/permanent atrial fibrillation) at screening, and ≥1 of the following (documented by echocardiography within 12 months prior to or at screening): * Septal é \